Vehicle lift with trailer hitch or the like

ABSTRACT

A trailer hitch or other auxiliary member is attached to the rear end of a vehicle (e.g. a cargo truck) in associated relation to a rear end lift, such that the hitch is free to move independently of the lift linkage when the lift is lowered for loading or unloading its deck, whereby the hitch may assume a noninterfering relation both to the ground surface and the lift linkage in such lowered position; whereas the movement of the lift to a stored position will automatically lock the hitch to the vehicle in rigid relation thereto such that it will properly function as a hitch when towing a trailer.

[ Feb. 1, 1972 S Q t a 4st S mm b Um X A 6 OD 4 2,617,628 11/1952 Wagner3,495,726 2/1970 Goldhofer...

3,534,874 /1970 Long........... 3,545,791 12/1970 [54] VEHICLE LIFT WITHTRAILER HITCH OR THE LIKE [72] Inventor: Morris D. Robinson, 1509 W.132nd St.

Gardena, Calif. 90249 Apr. 6, 1970 Primary Examiner-Albert J MakayAssistant Examiner-Robert J. Spar Att0rneyLynn H. Latta [22] Filed:

Appl, No.:

[57] ABSTRACT A trailer hitch or other auxiliary member is attached tothe [52] US. Cl. P, 214/86 A, 214/130,

rear end ofa vehicle (eg a cargo truck) in associated relation to a rearend lift, such that the hitch is free to move independently of the liftlinkage when the lift is lowered for loadi [51] Int. l/44 ng or M 9 a :3AI 1 ow ,7 m7 A I/ 9 4M W2 8 h c r m t 0 M .n F N 5 unloading its deck,whereby the hitch may assume a noninterfering relation both to theground surface and the lift linkage References Cited in such loweredposition; whereas the movement of the lift to a stored position willautomatically lock the hitch to the vehicle in rigid relation theretosuch that it will properly function as a hitch when towing a trailer.

UNITED STATES PATENTS 214/77 P 8 Claims, 5 Drawing Figures 3,375,946R1122 927 Gay et al... 2,589,654 3/1952 Archer VEHICLE LIFT WITH TRAILERHITCH OR THE LIKE BACKGROUND OF THE INVENTION Trailer hitches embodyinga ball, pintle, hook or other pivotal coupling element carried by abracket secured to the rear end of a vehicle chassis to provide a sturdyattachment of the coupling element to the vehicle in a rigid relationthereto which is required for effective trailer-pulling operation, arewell known and widely used. The problems of effecting such a rigidattachment to the vehicle where other attachments are not present insuch rear end area, are largely solved. However, the presence of a rearend power lift for loading and unloading cargo, has heretofore been anobstacle to the addition of an effective and satisfactory trailer hitch.

Trailer hitches having a rigid, fixed attachment to a vehicle equippedwith a cargo lift have not proven satisfactory. Where such a hitch hasbeen designed to project rearwardly from the vehicle to a satisfactorydistance for efficient trailer pulling and maneuvering, it hasobstructed the operation of the lift mechanism. This problem has beensolved in some instances by shortening the dimension of rearwardprojection of the hitch. But this has created another unsatisfactorycondition the coupling pivot being too close to the rear end of thevehicle, has created cornering interference between vehicle and traileron even moderately short radius turns.

Other attempts to solve these problems by attaching the hitch to thevehicle so as to provide for manual vertical adjustment of the hitch forstorage while using the lift, have likewise proven unsatisfactorybecause of the additional time and effort involved in the manualmanipulation of the hitch.

The increasing awareness of the need for safety devices on vehicles hasemphasized the importance of what has become known as an underridedevice (bumper) for preventing a following vehicle from intruding belowthe bed of a prece;ing vehicle, and the need for improvement therein.Such devices as are presently available (for fixed attachment to atruck) are not compatible with operation of an associated lift.

SUMMARY OF THE INVENTION The invention provides a combination of liftand hitch (or other auxiliary device such as an underride device) bothattached to the rear end ofa truck or other vehicle in a commonattachment area, but with independent connections such that they canswing vertically with partial independence of one another so that thehitch can move out of the way of the lift as the latter is lowered toleading-unloading position, and can be arrested by contact with theground, yet avoiding inter ference with the lifts descent. The inventionprovides lost-motion linkage interconnecting the hitch and lift linkageto raise the hitch to operative position in response to elevation of thelift to stored position, together with stop mechanism cooperating withsuch raising linkage to rigidify the lift in its operative position whenthe lift reaches the stored position. The pull of the trailer maintainsupward pressure of the hitch against the lift.

The general object of the invention is to provide a combination of liftand hitch interconnected for operation in the manner outlined above.Specific further objects are to provide such a lift-hitch combination:

1. Of relatively simple yet sturdy and durable construction such as towithstand the rigorous conditions of operation of truck lift and trailerhitch operations;

2. Avoiding undesirable interference between the hitch and the liftlinkage;

. In which the hitch extends rearwardly to a sufficient extent to avoidcornering interference between truck and trailer during short radiusturns;

4. Having ample clearance above the hitch coupler pivot and below thelift linkage to provide for unhindered hitching and unhitchingoperations;

. In which the pull of the trailer will have a resultant of upwardpressure of the hitch against the lift linkage such as to assist inholding the lift in its stored position, largely relieving the latchmechanism of the holding load and substantially eliminating anylooseness in the latching connection that might otherwise exist. with acorresponding reduction in vertical vibration of the lift and consequentwear on its latching parts.

DESCRIPTION Other objects and advantages of the invention will becomeapparent in the following specifications and appended drawings, wherein;

FIG. I is a left side elevational view of a combination lift and hitchembodying the invention, the lift being in stored position and the hitchin operative position;

FIG. 2 is a fragmentary rear elevational view of the same;

FIG. 3 is a left side elevation of the same, with the left in itslowered, extended position and the hitch in a retracted, noninterferingposition with relation to the lift;

FIG. 4 is a horizontal sectional view taken on line 4-4 of FIG. 1,showing the hitch in plan; and

FIG. 5 is a fragmentary side view showing a modified form of stopmechanism.

Referring now to the drawings in detail, I have shown therein, as anexample of one form in which the invention can be embodied, a trailerhitch H and lift L both attached, by means of a common mount M, to therear end of the chassis of a vehicle T which, for example, may be acargo truck; and operated by an hydraulic unit C.

Mount M may be of the construction shown in Robinson et al. U.S. Pat.No. 3,251,488, issued May 17, [966, comprising a transverse horizontalmount tube 11 suspended on mount plates 12 secured to and depending fromthe truck chassis rails 13, and sets of laterally spaced mount ears 14between which the linkage arms of lift L are pivoted on verticallyspaced transverse pivots 15, I6.

Lift L can be of the type wherein a lift deck (platform) 21 is hinged at25 on a transverse horizontal axis to a hinge bracket 22 which issupported in a nontilting vertical attitude, for vertical translationalswinging movement, by pairs of lift arms 23 and parallel arms 24 whichare pivoted to the bracket 22 by pivots which are vertically spaced likemount pivots 15, I6 so as to provide a parallelogram lift linkageincluding the bracket 22 on which deck 21 is cantilever supported at alllevels of elevation and lowering when swung on its hinge pivots 25 froma folded position shown in FIGS. 1 and 4 to an extended position shownin FIG. 3.

Hydraulic cylinder unit C is connected between a pivot 30 anchored tomount M and a pivot 31 carried by a bracket 32 secured to a transversespacer bar 33 bridging between lift arms 23, in accordance withwell-known prior art.

As shown in FIG. 2, the linkage arms 23, 24 move in separate verticalplanes which are laterally spaced to allow overlapping of the arms asviewed in side elevation while avoiding interference between them. Inthe type of lift disclosed by way ofexample, the parallel arms 24 are onthe outside and the lift arms 23 are embraced between arms 24, althoughit should be understood that a reverse arrangement could be utilized orthey could be in the same plane.

Hitch mechanism H comprises a hitch frame 35 embodying lateral arms 36pivoted to mount M on pivots which, for the purpose of simplification,can be the linkage-mount pivots 15, although not necessarily so. Arms 36have swinging free ends bridged by a crossbeam 37 on which is mountedthe hitch ball 38 or an equivalent pivotal coupling device. Frame 35 issuitably braced against side sway, as by means of diagonal bracing 39(FIG. 5). Secured firmly to the outer faces of arms 36 adjacent theirmount pivots 15, as by welding, are respective upwardly projecting stopfingers 40. Fingers 40 are in loose embracing relation to lift linkageparallel arms 24 and are positioned to engage against stop blocks 41secured to the outer faces of arms 24 when the linkage is fully raisedand the deck stored as in FIG. 1. Such engagement effectively limitsupward movement of the hitch frame 35, locking it against movement abovethe operative position of the hitch shown in H0. 1.

Secured to the outer faces of lift arms 23 and thus rigidly associatedtherewith, are a pair of hitch support arms 45 which extend downwardlyin substantially vertical postures when the lift linkage is in thestowed position of FIG. 1. Arms 45 are disposed in vertical planes suchas to clear the parallel arms 24 and the hitch frame arms 36 which aredisposed in planes outwardly of lift arms 23 (e.g., in the same planesas parallel arms 24). A satisfactory arrangement is one in which theplanes of hitcharms 45 are disposed between the planes of lift arms 23and 24, as shown. It is also possible to locate the arms 45 inwardly ofarms 23. Furthermore, hitch arms 35 can be located inwardly of lift arms23 and inwardly of arms 45. Arms 45, instead of being secured to lateralfaces of arms 23, could be integral, coplanar extensions of those arms.It also is possible to have the arms 45 secured to and carried by theparallel arms 24 and in clearing relation to lift arms 23, the essentialaspect of the invention being that arms 45 are carried by one arm of aparallelogram structure having an opposed generally parallel armcarrying a locking element which determines an upward limit of movementof the hitch frame. Support arms 45 are bridged at their lower ends by acrossbar 46 which is secured to arms 45, (e.g., by extending throughthem) and has projecting ends adapted to engage beneath hitch frame arms36 so as to transmit lift to frame 35 during elevation of the liftlinkage toward the stored position of FIG. 1, and to elevate the hitchframe to its operative position shown in FIG. 1. The parts are soarranged that in that position the fingers 40 will contact stop blocks41 so as to prevent further elevation of hitch frame 35. At the sametime the frame 35 will be held against downward movement by thesupporting action of crossbar 46. Thus it will be locked againstvertical movement in either direction and thus rigidly locked to thetruck chassis for effective trailer hitch operation.

When the lift is lowered toward the loading-unloading position of FIG.3, in fingers 40 will move away from the stop blocks 41, with aspreading action developing gaps between them of sufficient width tofree the hitch frame 35 for lost motion between it and the lift arms 23.Such lost motion will occur when the hitch lowered 35 comes to restagainst the ground surface G as shown in FIG. 3, and will allow the liftto continue its descent with the support arms 45 sliding downwardly andforwardly between the hitch frame arms 36 until the lift mechanismattains a fully lowered position which may, for example, be limited bycontact of deck 21 and/or its supporting parts against ground surface Gas in FIG. 3, or by contact of arms 23 against hitch frame crossbeam 37,also in dicated in H6. 3. The arrival of deck 21 at such a fully loweredposition will not be hindered by support arms 45, which are so arrangedin relation to their carrying arms 23 as to clear the ground surface G,swinging forwardly just above and substantially parallel thereto asindicated by broken arcuate line 50in FIG. 3.

The spreading action between stop parts 40, 41 is provided for byattaching them to the arms 24, 36 respectively in an arrangement suchthat the radius of arcuate movement of blocks 41 is much less than thatof the end of fingers 40 where they contact blocks 41. Thus during thedownward movement of hitch frame 35 prior to its being arrested bycontact with ground surface G, the rate of angular movement of fingers40 being substantially the same as that of blocks 41, the amplitude ofcircumferential movement of the tips of fingers 40 will exceed that ofblocks 41 by a ratio equivalent to the ratio of their respective radiiof arcuate movements. Thus it is important that the fingers 40 reachfrom frame 35 across to the arms 24, for maximum value of this ratio.

As shown in FIG. 5, the stop blocks 41A can be engaged by the tips ofstop fingers 40A instead of by the sides of the fingers as in FIGS. 1-3,

It may be noted that in this operative position, hitch frame 35, whenelevated to a proper level for coupling a trailer drawbar to itscoupling ball 38, projects rearwardly beyond the support bars 45, and isspaced below the linkage of lift L with ample clearance space so thatthe trailer may be easily coupled and uncoupled without interferencewith the lift linkage. The invention makes it possible to have the hitchframe extend rearwardly to provide amply for short radius turns withoutcornering interference between truck and trailer.

The hitch frame 35, in its operative position of FIG. I, positions thecoupling ball 38 at a level below the line of draft from the axis ofdraft pivots 15 to the point of attachment of the trailer drawbar (notshown) to the trailer, and consequently the pull on the trailer willhave a resultant of upward force at coupling ball 38 which will beapplied to the lift to assist in maintaining it in stored position.

While the apparatus has been shown and described herein in terms of anassembly of trailer bitch and lift, it is to be understood that theinvention also contemplates a similar assembly of lift and any otherauxiliary member of comparable proportions, such as a retractable bumperor underride device, which it may be desired to attach to the rear endof a vehicle equipped with a lift, and the appended claims are intendedto embrace such other devices as well as hitches.

1 claim:

1. In a combined lift and auxiliary member for rear end attachment to avehicle, in combination:

a lift linkage including arms and means for mounting them to the rearend of a vehicle for upward swinging movements of their free ends;

an auxiliary member including a frame;

means for attaching the forward extremity of said frame to said vehiclenear the area of mounting said arms, for vertical swinging of the rearextremity of said frame generally below said arms;

support means carried by said linkage and having means for lost-motionsupporting engagement with said frame from below for elevating the framewhen said linkage is raised;

said support means comprising support arms depending from said linkagearms in crossed, relatively movable relation to said frame;

said frame being open and including side arms pivoted to said attachingmeans;

said support arms passing through said frame inwardly of and adjacentsaid side arms;

said support means including a crossbar extending through the lower endsof said support arms and having end portions projecting beneath saidside arms;

and stop elements engageable upon elevation of said frame to an upperlimit position and cooperating with said support means to lock saidframe against vertical movement so as to establish a rigid connectionbetween said frame and vehicle.

2. in a combined lift and auxiliary member for rear end attachment to avehicle, in combination:

a lift linkage including arms and means for mounting them to the rearend of a vehicle for upward swinging movements of their free ends;

an auxiliary member including a frame;

means for attaching the forward extremity of said frame to said vehiclenear the area of mounting of said arms, for vertical swinging of therear extremity of said frame generally below said arms;

support means carried by said linkage and having means for lost-motionsupporting engagement with said frame from below for elevating the framewhen said linkage is raised;

and stop elements engageable upon elevation of said frame to an upperlimit position and cooperating with said support means to lock saidframe against vertical movement so as to establish a rigid connectionbetween said frame and vehicle;

said lift linkage arms being embodied in a parallelogram arrangement ofupper and lower pairs of arms connected to said mounting means byvertically spaced pivots;

said support arms means being carried by one of said lower pairs oflinkage arms;

and said stop elements including parts attached to the other pair ofsaid upper linkage arms. 3. The combination defined in claim 2, saidstop elements including fingers rigidly anchored to said frame andprojecting upwardly for abutting engagement with said parts; 5

said fingers moving away from said parts during downward movement ofsaid linkage arms and frame to provide lostmotion gaps between saidfingers and parts.

4. The combination defined in claim 2;

said stop elements being located near the axis of said vertil0 callyspaced pivots;

said support means being disposed between said stop elements and saidrear extremity of said frame.

5. The combination defined in claim 1;

said stop elements being located adjacent the axis of attachment ofsaidframe;

said support means being located between said stop elements and saidrear extremity of said frame;

whereby upon downward movement of said frame and linkage arms, said stopelements will separate to provide lostmotion gaps between them such thatsaid frame and linkage arms may approach one another during theirdownward movements.

6. In a combined lift and auxiliary member for rear end attachment to avehicle, in combination:

a lift linkage including arms and means for mounting them to the rearend of a vehicle for upward swinging move ments of their free ends;

an auxiliary member including a frame;

means for attaching the forward extremity of said frame to said vehiclenear the area of mounting said arms, for vertical swinging of the rearextremity of said frame generally below said arms;

support means carried by said linkage and having means for lost-motionsupporting engagement with said frame from below for elevating the framewhen said linkage is raised; and stop elements engageable upon elevationof said frame to an upper limit position and cooperating with saidsupport means to lock said frame against vertical movement so as toestablish a rigid connection between said frame and vehicle;

said auxiliary member being a trailer hitch including a coupling pivotelement on the rear extremity of said frame.

7. The combination defined in claim 6;

said hitch, when in operative position, supporting the pivot element ata level sufficiently low to be below the line of draft from the vehicleto the trailer, so that the pull on the trailer will develop a resultantof upward pressure of the hitch against the lift.

8. The combination defined in claim 2;

said support means being carried by said lower linkage arms;

and said stop element parts being attached to said upper linkage arms.

1. In a combined lift and auxiliary member for rear end attachment to a vehicle, in combination: a lift linkage including arms and means for mounting them to the rear end of a vehicle for upward swinging movements of their free ends; an auxiliary member including a frame; means for attaching the forward extremity of said frame to said vehicle near the area of mounting said arms, for vertical swinging of the rear extremity of said frame generally below said arms; support means carried by said linkage and having means for lostmotion supporting engagement with said frame from below for elevating the frame when said linkage is raised; said support means comprising support arms depending from said linkage arms in crossed, relatively movable relation to said frame; said frame being open and including side arms pivoted to said attaching means; said support arms passing through said frame inwardly of and adjacent said side arms; said support means including a crossbar extending through the lower ends of said support arms and having end portions projecting beneath said side Arms; and stop elements engageable upon elevation of said frame to an upper limit position and cooperating with said support means to lock said frame against vertical movement so as to establish a rigid connection between said frame and vehicle.
 2. In a combined lift and auxiliary member for rear end attachment to a vehicle, in combination: a lift linkage including arms and means for mounting them to the rear end of a vehicle for upward swinging movements of their free ends; an auxiliary member including a frame; means for attaching the forward extremity of said frame to said vehicle near the area of mounting of said arms, for vertical swinging of the rear extremity of said frame generally below said arms; support means carried by said linkage and having means for lost-motion supporting engagement with said frame from below for elevating the frame when said linkage is raised; and stop elements engageable upon elevation of said frame to an upper limit position and cooperating with said support means to lock said frame against vertical movement so as to establish a rigid connection between said frame and vehicle; said lift linkage arms being embodied in a parallelogram arrangement of upper and lower pairs of arms connected to said mounting means by vertically spaced pivots; said support arms means being carried by one of said lower pairs of linkage arms; and said stop elements including parts attached to the other pair of said upper linkage arms.
 3. The combination defined in claim 2, said stop elements including fingers rigidly anchored to said frame and projecting upwardly for abutting engagement with said parts; said fingers moving away from said parts during downward movement of said linkage arms and frame to provide lost-motion gaps between said fingers and parts.
 4. The combination defined in claim 2; said stop elements being located near the axis of said vertically spaced pivots; said support means being disposed between said stop elements and said rear extremity of said frame.
 5. The combination defined in claim 1; said stop elements being located adjacent the axis of attachment of said frame; said support means being located between said stop elements and said rear extremity of said frame; whereby upon downward movement of said frame and linkage arms, said stop elements will separate to provide lost-motion gaps between them such that said frame and linkage arms may approach one another during their downward movements.
 6. In a combined lift and auxiliary member for rear end attachment to a vehicle, in combination: a lift linkage including arms and means for mounting them to the rear end of a vehicle for upward swinging movements of their free ends; an auxiliary member including a frame; means for attaching the forward extremity of said frame to said vehicle near the area of mounting said arms, for vertical swinging of the rear extremity of said frame generally below said arms; support means carried by said linkage and having means for lost-motion supporting engagement with said frame from below for elevating the frame when said linkage is raised; and stop elements engageable upon elevation of said frame to an upper limit position and cooperating with said support means to lock said frame against vertical movement so as to establish a rigid connection between said frame and vehicle; said auxiliary member being a trailer hitch including a coupling pivot element on the rear extremity of said frame.
 7. The combination defined in claim 6; said hitch, when in operative position, supporting the pivot element at a level sufficiently low to be below the line of draft from the vehicle to the trailer, so that the pull on the trailer will develop a resultant of upward pressure of the hitch against the lift.
 8. The combination defined in claim 2; said support means being carried by said lower linkage arms; and said stop element parts being attached to said upper linkage arms. 